CAJ | 학술논문

将具有不同α片层厚度的两种转变组织的TAl5合金分别在Thermecmaster-Z型热模拟试验机上进行等温恒应变速率压缩试验,研究了温度为1000～1100℃、应变速率为0.001～10s~(-1)时合金的热变形行为.结果表明,两种不同组织的TAl5合金在β相区相同热力参数变形时,真应力-真应变曲线的形貌和真应力值基本相同,变形激活能为(170±2)kJ/mol,且微观组织特征基本相似,以β相的动态再结晶为主.但在1050℃、0.01～1s~(-1)变形时,细片层组织的合金发生β相动态再结晶的体积分数总是略高于粗片层组织的合金,这可能与细片层组织的合金较早发生α→β相转变、且β相也较早开始再结晶有关.
장구유불동α편층후도적량충전변조직적TAl5합금분별재Thermecmaster-Z형열모의시험궤상진행등온항응변속솔압축시험,연구료온도위1000～1100℃、응변속솔위0.001～10s~(-1)시합금적열변형행위.결과표명,량충불동조직적TAl5합금재β상구상동열력삼수변형시,진응력-진응변곡선적형모화진응력치기본상동,변형격활능위(170±2)kJ/mol,차미관조직특정기본상사,이β상적동태재결정위주.단재1050℃、0.01～1s~(-1)변형시,세편층조직적합금발생β상동태재결정적체적분수총시략고우조편층조직적합금,저가능여세편층조직적합금교조발생α→β상전변、차β상야교조개시재결정유관.
Hot compression tests of two TAl5 alloys with different α-lamellar thickness, which is respectively transformed at furnace coolling and air cooling, were conducted using Therme-cmastor-Z hot working simulator. Hot deformation behavior was investigated at 1000～1100℃ and strain rate of 0.001～10 s~(-1). The results show that the shapes and stress values of the true stress-strain curves of the two TAl5 alloy are identical and the activation energy is nearly (170±2) kJ/mol. The microstructure characteristic of the two TAl5 alloy is similar under the same hot deformation parameters, which is mainly manifested by dynamic re-crystalized β grains. The re-crystalized β volume fraction of the TAl5 alloy with thin lamellar microstructure is slightly higher than that with thick lamellar at 1050℃ and strain rate of 0.01～1 s~(-1). This may be because the microstructure transformation from α to β phase starts earlier in thin lamellar than in thick lameUar, and β phase re-crystalizes earlier.